#include<iostream>
#include<string.h>
using namespace std;
int main(){
  char str[256];
  //cin.getline(str,256);
  fgets(str,256,stdin);
  int sum=0;
  int n=0;
  while(str[n]){
    if(str[n]>='0'&&str[n]<='9')
      sum++;
    n++;
  }
  cout<<sum;
}